Three dimensional fabric and method for producing the same

ABSTRACT

The present invention relates to a three dimensional fabric including a warp layer consisting of a plurality of warps arranged in parallel along a longitudinal direction of the fabric, bias threads arranged in inclined directions with respect to the longitudinal direction of the fabric in a place parallel to the warp layer, and a vertical thread arranged in a thicknesswise direction of the fabric such that it perpendicularly intersects the warps. It also relates to a method of producing the fabric. Where such fabric is employed for a composite material in which a resin or the like is used as a matrix, the composite material deforms less under the influence of forces acting in an oblique direction. It therefore has an increased range of applications as a structural material comparing with a conventional 3-axis three dimensional fabric. Further, the subject of the present invention resides in provision of a three dimensional fabric having an arrangement of threads of such bias directions and a producing process by which such three dimensional fabric can be produced comparatively readily. A bias thread layer is composed of a large number of continuous bias threads which are arranged such that they are inclined symmetrically to each other with respect to a longitudinal direction of the fabric in a plane parallel to the warp layer. Each pair of bias thread layers make a set. The engaging positions of the bias threads with a set made of each two thereof which are in an engaging condition with engaging portions of a feeding device disposed between the cloth fell position and a bias thread supplying section are moved by a predetermined pitch in opposite directions to each other for each of the bias thread layers along widthwise directions of the fabric by an action of the feeding device. Such movement of the engaging positions and insertion of vertical threads are performed alternately.

TECHNICAL FIELD

This invention relates to a three dimensional fabric including a warplayer comprising a plurality of warp strings arranged in parallel with alongitudinal direction of the fabric, bias threads arranged in inclineddirections with respect to the longitudinal direction of the fabric in aplane parallel to the warp layer, and a vertical thread arranged in athicknesswise direction of the fabric in a perpendicularly intersectingcondition to the warp strings, and also to a method for producing thefabric.

BACKGROUND

Composite materials having a three dimensional fabric that includesthreads extending in the X, Y and Z directions are expected to be widelyused as structional materials for rockets, aircraft, automobiles, marinevessels and buildings. Such fabrics include a multiplicity of warpstrings, and vertical threads and wefts woven perpendicularly in betweencolumns and rows of the warp strings. The fabric is used as a core andimpregnated with matrix of a resin or an inorganic substance.

Further, as a method for producing the three dimensional fabric of thetype mentioned, various processes are conventionally proposed. (Forexample, Japanese Patent Publication No. 38673/1979 and Japanese PatentPublication No. 14624/1976). While three dimensional fabrics of the typementioned are strong enough against tensile loads, compressive loads andbending loads acting in the X, Y and Z directions, they have thedrawback that the amount of deformation caused by a force acting in aninclined direction with respect to the axial direction is great.

It is a first object of the present invention to provide a novel threedimensional fabric wherein the amount of deformation by a force actingin an inclined direction is decreased.

It is a second object of the present invention to provide a method forproducing a three dimensional fabric readily.

DISCLOSURE OF THE INVENTION

In order to attain the first object described above, according to thepresent invention, there is provided a three dimensional fabric whichcomprises a warp layer consisting of a plurality of warp stringsarranged in parallel with a longitudinal direction of the fabric, biasthread layers comprising a multiplicity of continuous bias threadsarranged in such a manner as to be inclined symmetrically to each otherwith respect to the longitudinal direction of the fabric in a planeparallel to the warp layer, each pair of the bias thread layers making aset, and a plurality of vertical threads arranged perpendicular to thewarp strings and in a thicknesswise direction of the fabric. Acontinuous vertical thread extend between adjacent columns of the warplayer and is arranged to run back and forth between the opposite outersides of the columns.

In addition to the construction described above, a weft may be arrangedin a widthwise direction of the fabric such that it extendsperpendicular to the warp strings. When the three dimensional fabrichaving bias threads as described above, is used as a core of a compositematerial in which a resin or the like is used as a matrix, the amount ofdeformation by a force acting in an oblique direction upon the compositematerial is decreased by the action of the bias threads. This increasethe range of applications for such a structural material. By using alarge number of bias threads which are continous and folded back in theindividual bias thread layers, it is easy to continously weave the threedimensional fabric. When the fabric is used for a composite material,the rigidity against a tensile load, a bending load and some other loadsis high and the strength is improved.

With the three dimensional fabric wherein no weft is present, in-plane3-axis and in-plane isotropy can be obtained by the warp strings and thebias threads which are arranged such that they are inclinedsymmetrically to each other with respect to the longitudinal directionof the fabric in a plane parallel to the warp layer. Compared to anin-plane 4-axis, totally 5-axis three dimensional fabric in which a weftexists, such three dimensional fabric is simple in structure. It is alsopossible to increase the thickness of the bias threads to increase thefiber orientation ratio of the bias threads. The bias threads whichconstitute each of the bias thread layers each two of which makes a setmay be disposed either such that they have and inclination of onedirection or such that they are inverted cyclically.

In and embodiment of the three dimensional fabric having a plurality ofbias thread layer sets wherein at least one set of the bias threadlayers are folded back intermediately of the full width of the fabric,it is easy to obtain a three dimensional fabric wherein the warp densityin the widthwise direction of the fabric is uniform. Those of the biasthread layers of at least one set of the plurality of sets may be foldedback with a predetermined width smaller than the width of the fabricsuch that the thickness of the fabric may vary in its widthwisedirection. Further, the three dimensional fabric may have a plurality ofsets of the bias thread layers each two of which make a set, and theinclination angle of the bias threads of those of the bias thread layersof at least one set may be different from the inclination angle of thebias threads of those of the bias thread layers of the other set orsets. With the construction, where the three dimensional fabric is usdas a core of a composite material, comparing with another compositematerial which employs a three dimensional fabric wherein individualbias threads of a plurality of sets of bias thread layers have the sameinclination angle, the in-plane uniformity is improved and the amount ofdeformation by a force acting in an oblique direction upon the compositematerial is further reduced. Consequently, the a wide variety ofapplications as a structural material is realized.

In order to attain the second object, according to a producing processof the present invention, a plurality of warp strings are stretched in aplurality of layers in a thicknesswise direction of the fabric such thatthey extend in a longitudinal direction of the fabric. A plurality ofbias threads are stretched in parallel to the warp layers such that eachtwo layers may make a set. A vertical thread is inserted in thethicknesswise direction of the fabric and a loop is formed at an endthereof. A selvage thread is inserted into the end loop of the verticalthread. Then the vertical thread is drawn back. When the vertical threadis postioned outside the warp strings and the bias threads, the actionof a feeding device moves each pair of bias threads to an engagingposition. The feeding device is positioned between the coil fellposition and a bias thread supplying section and is oriented in thewidthwise direction of the fabric. The engaging positions of a pair ofbias thread layers engage with the engaging portions of the feedingdevice. These bias thread engaging positions are moved by apredetermined pitch in opposite directions along the widthwise directionof the fabric to arrange the bias threads obliquely with respect to thelongitudinal direction of the fabric. Thereafter, insertion of thevertical thread is performed again. With this construction, a 4-axisthree dimensional fabric can be woven. Since movement of the biasthreads in the widthwise directions is performed by a simple method,wherein the engaging portions of the feeding device disposed between thebias thread supplying section and the cloth fell position are moved inthe predetermined direction, the device for carrying out this method issimplified.

According to another structure, a plurality of warp strings arestretched in a plurality of layers in a thicknesswise direction of thefabric in a condition wherein they extend in a longitudinal direction ofthe fabric. A plurality of bias threads are stretched in parallel to thewarp layers such that each two layers may make a set. Insertion of avertical thread in the thicknesswise direction of the fabric andinsertion of a weft in a widthwise direction of the fabric areperformed. After completion of insertion of the weft by one cycle, thevertical thread connecting to the fabric being woven is disposed outsidethe warp strings and the bias threads. An action of a feeding devicearranged in the widthwise direction of the fabric between the cloth fellposition and a bias thread supplying section, the engaging positions ofthe bias threads which are in an engaging condition with engagingportions of the feeding device are moved by a predetermined pitch inopposite directions to each other for each of the bias thread layersalong the widthwise direction of the fabric to arrange the bias threadsobliquely with respect to the longitudinal direction of the fabric; andthen insertion of the vertical thread is performed again. With thepresent structure, a 5-axis three dimensional fabric is produced.

Where the processing process is constituted such that, when the biasthreads are to be arranged obliquely with respect to the longitudinaldirection of the fabric, by an action of a feeding device which isarranged in the widthwise direction of the fabric between the cloth fellposition and the bias thread supplying section and wherein engagingportions which are provided at two stages so that they may be engagedwith the bias threads of each of the bias thread layers arecirculatively moved in a predetermined direction along a moving route inthe form of loop extending in the widthwise direction of the fabric, theengaging positions of the bias threads which are in an engagingcondition with the engaging portions of the feeding device are moved inthe opposite directions to each other between adjacent ones of the biasthread layers while the bias threads connecting from the engagingportions to the bias thread supplying section are moved, upon movementof the engaging portions, in the same direction, the bias threads of thetwo adjacent upper and lower layers which connect from the cloth fell tothe supplying section by way of the individual engaging portions arealways kept in a parallel condition, and the bias threads of each layerare arranged obliquely with respect to the longitudinal direction suchthat they may have inclinations of one direction.

Further, where the bias threads each two of which make a set arestretched by a plurality of sets and, when the bias threads are to bearranged obliquely with respect to the longitudinal direction of thefabric by an action of a feeding device, the feeding pitch of a feedingdevice corresponding to at least one of the plurality of sets of thebias threads is made different from the feeding pitch of any otherfeeding device, such bias threads are arranged obliquely at a differentinclination angle from the other bias threads.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 to 21 show a first embodiment of the present invention. FIG. 1is a partially broken away schematic perspective view of a threedimensional fabric;

FIG. 2 is a partially broken away plan view, of the three dimensionalfabric;

FIG. 3 is a schematic side elevational sectional view showing a weavingcondition of the three dimensional fabric;

FIG. 4 is a schematic plan view of the same;

FIG. 5 is a schematic perspective view of a shedding device;

FIG. 6 is a schematic perspective view of a vertical thread rapier;

FIG. 7 is a schematic perspective view showing an engaging conditionbetween bias threads and screw shafts;

FIGS. 8 to 15 are schematic sectional views illustrating operation of abias thread feeding device;

FIGS. 16 to 21 are schematic side elevational views illustrating aweaving operation.

FIGS. 22 to 27 show a second embodiment.

FIG. 22 is a schematic perspective view, partly broken, of a threedimensional fabric;

FIGS. 23 to 27 are schematic side elevational views illustrating aweaving operation;

FIGS. 28 and 29 are schematic perspective views of essential parts of athread feeding device of a modified example.

FIGS. 30 to 33 show a third embodiment.

FIG. 30 is a schematic perspective view, partly broken away, of a threedimensional fabric;

FIG. 31 is a plan view, partly broken away, of the three dimensionalfabric;

FIGS. 32 and 33 are schematic sectional views showing a set condition ofbias threads to screw shafts.

FIGS. 34 and 35 show a fourth embodiment.

FIG. 34 is a plan view, partly broken, of a three dimensional fabric;

FIG. 35 is schematic sectional view showing a set condition of biasthreads to screw shafts;

FIGS. 36 to 41 show a fifth embodiment.

FIG. 36 is a schematic perspective view, partly broken away of a threedimensional fabric;

FIGS. 37 to 39 are plan views, partly broken away, of the threedimensional fabric;

FIGS. 40 and 41 are schematic sectional views showing a set condition ofbias threads to screw shafts;

FIG. 42 is a schematic side elevational view of a sixth embodiment.

FIGS. 43 to 60 show a seventh embodiment.

FIG. 43 is a schematic sectional view, partly broken away, of a threedimensional fabric;

FIG. 44 is a plan view, partly broken away, of the three dimensionalfabric;

FIG. 45 is a schematic side elevational sectional view illustrating aweaving condition of the three dimensional fabric;

FIG. 46 is a schematic plan view of the same;

FIG. 47 is a schematic view of essential part of a bias thread feedingdevice;

FIG. 48 is a sectional view illustrating the relationship between railsand guide blocks;

FIGS. 49 to 54 are sectional views illustrating operation of the biasthread feeding device;

FIG. 55 is a schematic front elevational view of a bias thread supplyingsection;

FIG. 56 is a sectional view illustrating a supporting condition of abias thread bobbin; FIGS. 57 to 60 are schematic side elevational viewsillustrating a weaving operation;

FIGS. 61 to 64 show an eighth embodiment.

FIG. 61 is a schematic side elevational sectional view illustrating aweaving condition;

FIG. 62 is a plan view of the same;

FIG. 63 is a schematic perspective view of a three dimensional fabric;and

FIG. 64 is a plan view, partly broken, of the three dimensional fabric.

BEST MODE FOR CARRYING OUT THE INVENTION

In the following, the present invention will be described more in detailwith reference to the drawings.

EMBODIMENT 1

First, a first embodiment of a 5-axis three dimensional fabric and amethod for producing the same will be described with reference to FIGS.1 to 21.

As shown in FIGS. 1 and 2, a three dimensional fabric F is includes awarp layer having a multiplicity of warp strings z stretched in aplurality of columns and a plurality of rows (four columns and threerows in the figures). The warp strings z extend in parallel with alongitudinal direction of the three dimensional fabric F. A multiplicityof vertical threads y are woven perpendicular to the warp strings inbetween adjacent columns. Thus the vertical threads are arranged in awidthwise direcion relative to the fabric such that they are continuousfor the individual columns. A multiplicity of bias threads B arearranged in between the individual rows of the warp strings z such thatthey are symmetrically aligned with respect to the longitudinaldirection of the frabric in a plane parallel to the warp layer. The biasthreads B are folded back continuously at the opposite ends of thefabric F. Wefts x extend in widthwise directions of the fabric betweenthe warp layer and a bias threads layer. The wefts x run perpendicularto the warp strings z. Each of the vertical threads y is verticallyfolded back to form loops at ends and inserted to between two adjacentwarp strings z. A weft x is inserted in the end loop of such verticalthread y in order to prevent coming off of the end loop. Also each ofthe wefts x is folded to form an end loop and inserted between thethread y. Meanwhile, the bias threads B are arranged in a zigzagpattern, respectively, so as to be folded back at widthwise end portionsof the three dimensional fabric F such that two layers thereof may makea set, and they are arranged in such a condition that the bias threads Bin an upper layer and bias threads B in a lower layer intersect eachother.

In FIG. 1, the warp strings z, wefts x, vertical threads y and biasthreads B are illustrated as being spaced from each other in order toclearly indicate structure of the three dimensional fabric F. Actually,however, the threads are arranged closely to each other as shown in FIG.2. Further, where rovings such as carbon fiber with little twist areused for each of the threads, wefts x and vertical threads y which areindividually inserted in a folded condition forming a loop at an endthereof is overlapped, after weaving, with each other into a singlestring and integrated with each other as shown in FIG. 2.

The three dimensional fabric F is used as a composite material in whicha resin or the like is impregnated. Due to the presence of such biasthreads arranged in inclined directions with respect to the longitudinaldirection of the fabric, the amount of deformation by a force acting inan inclined direction is decreased in comparison with a compositematerial employing a conventional 3-axis three dimensional fabric as acore. The structure has paired bias thread layer sets which are composedof a large number of continuously folded back bias threads B. When thefabric F is used in a composite material, it has a high rigidity againsttensile loads, compressive loads, bending loads and some other loads andalso has improved strength.

An apparatus for weaving such a three dimensional fabric is shown inFIGS. 3 and 4. It concludes, a warp supplying section including a numberof warp beams 1 corresponding to the number of the rows of the warpstrings z, and a bias thread supplying section including a number ofbias thread beams 2a which is equal to one half the number of the biasthread layers. A thread supporting plate 3 has end portions of themultiplicity of warp strings z and bias threads B fastened thereto. Thewarp strings z are drawn out from the warp beams 1 and the bias threadsB are drawn out from the bias thread beams 2a. As weaving proceeds, thethread supporting plate is moved in a direction to draw up the threedimensional fabric F (to the left in FIGS. 3 and 4) by operation of adriving mechanish (not shown ) from a position in the proximity of acloth fell fram 4 disposed at a predetermined location. Warp sheddingdevices 5 and bias thread shedding devices are disposed to the rear ofthe cloth fell frame 4 (to the right in FIGS. 3 and 4).

Each of the warp shedding devices 5 includes, as shown in FIG. 5, aframe 7 having a width greater than that of the three dimensional fabricand having a height greater than the thickness of the three dimensionalfabric. A pair of guide rods 7a are secured to the frame 7 in a spacedrelationship by a distance sufficient to allow passage of the warpstrings z therebetween. The warp shedding devices 5 are moved up anddown by a driving mechanism (not shown). The bias thread sheddingdevices 6 are substantially similar in construction to the warp sheddingdevice 5. the distance between a pair of guide rods 7a is set greaterthan that of the warp shedding device 5 so that the bias threads B donot contact the guide rods 7a when a bias thread feeding device(described below) operates.

A vertical thread rapier 9 is disposed between the cloth fell frame 4and the warp shedding devices 5 and acts to insert, upon upward anddownward movement thereof, the vertical threads y. The vertical threadsare drawn out from a vertical thread supplying section 8 betweenindividual adjacent columns of the warp strings z. As shown in FIG. 6,the vertical thread rapier 9 includes a support body 10 which is movedup and down by a driving mechanism (not shown), and a plurality of pipes9a fitted in the support body 10. A predetermined number of verticalthreads y are simultaneously threaded in each column of the warp stringsz.

A guide plate 11 is disposed in front of the warp beams 1 and guides thewarp strings z and the bias threads B drawn out from the warp beams 1and the bias thread beams 2a, respectively. The guide plate 11 has aplurality of guide holes 11a formed at locations corresponding to upperends of the warp beams 1 and the bias thread beams 2a for guiding thewarp strings z and the bias threads B one by one therethrough. A tensionadjusting device 12 (shown on in FIG. 3) is provided between the guideplate 11 and each of the bias thread beams 2a for each of the biasthreads B drawn out from the bias thread beams 2a.

Warp guides 13 and bias thread feeding device 14 are disposed behind thetwo shedding devices 5 and 6. The warp guides 13 are formed from rodswhich are disposed at predetermined locations. Each warp guide has guidegrooves formed at a predetermined spaced relationship on a surfacethereof. As shown in FIG. 7, the bias thread feeding device 14 includestwo pairs of schrew shafts 15 and 16. The shaft screws have spiralgrooves 15a and 16a respectively which are formed in oppositedirections. The two pairs of screw shafts 15 and 16 are disposed forindividual movement between an operative position and a retractedposition. In the operative position, the shafts 15, 16 extend inparallel to the widthwise direction of the three dimensional fabric andmay individually engage the bias threads B. In the retracted position,the shafts 15, 16 do not engage the bias threads B. The three screwshafts 15 and 16 which are at the engaged position can be disposedalternately in the up and down directions.

The wefts x are inserted between adjacent rows of the warp strings z orbetween a row of warp strings z and a layer of the bias threads B. Theend of each wefts is formed into a loop and inserted in a foldedcondition by a weft rapier 17 (shown in FIGS. 18 and 20). The rapier 17has a beating function.

The weaving of a three dimensional fabric using the apparatus having thedescribed structure will be described hereinafter.

First, the feeding operation of the bias threads B by the bias threadfeeding device 14 will be described. Lateral movement of the biasthreads B in the width direction of the fabric is performed by rotatingthree of the screw shafts 15 and 16 in the same direction. The screwshafts are disposed at three vertical stages such that they extend inhorizontal directions. As shown in FIG. 8, the three screw shafts 15 and16 are disposed at the three vertical stages and extend in horizontaldirections while the remaining screw shaft 16 is disposed at itsretracted position. In the above condition, the bias threads B arearranged to engaged the spiral grooves 15a and 16a in the upper andmiddle state shaft screws at a predetermined pitch P. If the operativescrew shafts 15 and 16 are driven to rotate by two rotations in the samedirection, the bias threads B held in egagement with the screw shaft 15at the upper stage are moved one pitch P to the right. Meanwhile, thebias threads B held in engagement with the screw shaft 16 at the middlestage are moved by one pitch P to the left. Thereupon, the bias thread Bheld in engagement with the spiral groove 16a adjacent an end of thescrew shaft 16 disposed at the middle stage is disengaged from the screwshaft 16 and is now brought into engagement with the spiral groove 15aadjacent a base end of the screw shaft 15 disposed at the lower stage.Meanwhile, the bias thread B at an end of the screw shaft 15 disposed atthe upper stage is transferred to a location of a base end portion ofthe screw shaft 16 at the middle stage so that a condition of FIG. 9 isentered.

The screw shafts 15 and 16 disposed at the operative positions aretotated to successively perform lateral feeding of the bias threads B ina similar manner. Then, the bias threads B which have been in engagementwith the screw shaft 16 at the middle stage in the condition shown inFIG. 8 are all transferred to the screw shaft 15 disposed at the lowerstage. Meanwhile, the bias threads B which have been in engagement withthe screw shaft 16 at the middle stage so that a condition shown in FIG.10 is entered. After all of the bias threads B which have been inengagement with the screw shaft 15 disposed at the upper stage aretransferred from the screw shaft 15, the screw shaft 15 is movedbackwardly to its retracted position as shown in FIG. 11. At the sametime, the screw shaft 16 which has been disposed at the middle stage andthe screw shaft 15 which has been disposed at the lower stage are nowmoved upwardly by one stage distance to the upper stage and the middlestage, respectively. Then, the remaining screw shaft 16 which has beendisposed at the retracted position at the lower stage is moved forwardlyto the operative position at the lower stage. Meanwhile, the screw shaft15 is moved downward from the retracted position at the upper stage tothe retracted position at the lower stage to the position shown in FIG.12.

With the rotation of the screw shafts 15 and 16 in the same direction asdescribed above, the bias threads B remaining in engagement with thescrew shaft 15 disposed now at the middle stage are successively movedto the right by one pitch while they are successively transferred to thescrew shaft 16 disposed at the lower stage. Meanwhile, the bias threadsB remaining in engagement with the screw shaft 16 disposed at the upperstage are moved to the left while they are successively transferred tothe screw shaft 15 disposed at the middle stage.

After all of the bias thread B which have been in engagement with thescrew shaft 16 disposed at the upper stage are transferred to the screwshaft 15 disposed at the middle stage as shown in FIG. 14. Then, thescrew shaft 16 at the upper stage is moved backwardly to its retractedposition while the screw shaft 15 disposed at the middle stage.Meanwhile, the screw shaft 16 disposed at the lower stage are shiftedupwardly by one stage distance to the upper stage and the middle stage,respectively, as shown in FIG. 15. Then, the screw shaft 15 which hasbeen disposed at the retracted position at the lower stage is disposednow to the operative position. Then the screw shaft 16 which has beendisposed to the retracted position at the upper stage is moved downwardto the retracted position at the lower stage so that the condition shownin FIG. 8 is restored.

Thereafter, lateral feeding operation of the bias threads B is performedsuccessively in a similar manner. While the lengths of the bias threadsB along routes thereof between the guide plate 11 and the cloth fell arevaried to a great extent by lateral feeding of the bias threads B, thetension of the bias threads B is kept substantially constant by anaction of the tension adjusting devices 12.

Subsequently, a weaving procedure will be described hereinafter. Uponstarting of weaving of a three dimensional fabric, the yarn supportingplate 3 is disposed at a position in the proximity of the weaving frontframe 4. Warp strings z and bias threads B drawn out from the warp beam1 and the bias thread beam 2a, respectively, are set to be threadedthrough the guide holes 11a of the guide plate 11. The warp guides 13 orbias thread feeding device 14 and the warp shedding devices 5 or biasthread shedding devices 6 are fastened to the yarn supporting plate 3.

FIG. 16 illustrates a condition after completion of insertion of wefts xfor the fourth layer from the left of a three dimensional fabric F. Inthis condition, the vertical thread rapier 9 is disposed at its liftedposition while the warp shedding device 5 and the bias thread sheddingdevices 6 are all disposed at the respective lowered positions. In thecondition wherein the bias thread shedding devices 6 are disposed attheir lowered positions, the guide rods 7a of each of the bias threadshedding devices 6 are disposed at positions at which they are notengaged with a bias thread B inserted between the pair of guide rods 7a.In this condition, the bias thread feeding device 14 is driven in such amanner as described hereinabove, and each of the bias threads B is movedby one pitch P in a widthwise direction of the three dimensional fabric.Subsequently, as shown in FIG. 17, all of the warp shedding devices 5and the bias thread shedding devices 6 are disposed at their liftedpositions while the vertical thread rapier 9 is moved downward so that avertical thread y is inserted between each pair of adjacent columns ofthe warp strings z. Thereafter, each of the pipes 9a of the verticalthread rapier 9 is inserted, as shown in FIG. 4, between bias threads Bto the rear of an intersecting portion of the bias threads B disposed ina mutually intersecting condition, i.e., adjacent the bias threadshedding devices 6.

Subsequently, insertion of a weft x is performed between a warp z at thelower most stage and the vertical thread y by the weft rapier 17 havinga beating up function. Since the vertical thread rapier 9 is spaced fromthe position of the cloth fell, a downwardly directed portion of thevertical thread y is not pressed to the cloth fell position only bydownward movement of the vertical thread rapier 9. Rather they arepressed by insertion of the weft x to the lowermost stage. Thedownwardly directed portion of the vertical thread y is disposed at thecloth fell position in a perpendicularly intersecting condition with thewarp z as shown in FIG. 18. It is to be noted that, before insertion ofthe weft x is performed, beating may be performed to move the verticalthread y toward the cloth fell side.

Subsequently, the vertical thread rapier 9 is moved to the liftedposition so that the vertical thread y is folded back upwardly. Then,the warp shedding devices 5 and the bias thread shedding devices 6 aredisposed successively to their lowered positions from the side remotefrom the cloth fell frame 4 to form a shed, and insertion of the weft xinto the shed by the weft rapier 17. When the vertical thread rapier 9is moved to the lifted positon, an upwardly directed portion of thevertical thread y extending from the vertical thread rapier 9 to thecloth fell is disposed obliquely with respect to the cloth fell as shownin FIG. 19. As beating is performed simultaneously with insertion of theweft x by the weft rapier 17, the upwardly directed portion of thevertical thread y is successively disposed into a parallel condition tothe cloth fell as shown in FIG. 20. After a condition shown in FIG. 21is entered as a result of completion of insertion of the weft x into allof the stages, the yarn supporting plate 3 is moved so that the threedimensional fabric F is moved by one pitch until an end portion thereofis put into a condition shown in FIG. 16. Thereafter, a similar sequenceof operations are repeated so that the three dimensional fabric F havingthe substantially same structure as the three dimensional fabric shownin FIG. 1 is woven. The difference from the three dimensional fabric Fshown in FIG. 1 resides in that the number of rows of the warp strings zis greater by one.

EMBODIMENT 2

A second embodiment will be described with reference to FIGS. 22 to 27.In a three dimensional fabric F of the present embodiment, a weft x isinserted not only into a loop portion at a folded end of a verticalthread y inserted in a folded condition between adjacent columns of warpstrings z but also between each warp z and bias thread B so that thedensity of the wefts x is increased.

When a three dimensional fabric F of the type mentioned is to be woven,movement of bias thread B is performed in a similar manner as in thepreceding embodiment. That is, in a condition wherein the verticalthread rapier 9 is disposed at the lifted position while the warpshedding devices 5 and the bias thread shedding devices 6 are disposedat the respective lowered positions.

Subsequently, the vertical thread rapier 9 is inserted, and thereafter,the warp shedding devices 5 and the bias thread shedding devices 6 aresuccessively operated to the respective lifted positions from the clothfell frame 4 side so that sheds of the warp strings z and the biasthread B are formed successively from above while insertion of the weftx is performed into the sheds by the weft rapier 17 as shown in FIG. 24.Then, after insertion of the weft x into the shed at the lowermost stageis completed as shown in FIG. 25, the vertical thread rapier 9 is movedto the lifted position 9 so that the vertical threads y are folded back.

Subsequently, the yarn supporting plate 3 is moved so that the threedimensional fabric F is drawn up, and then the warp shedding devices 5and the bias thread shedding devices 6 are operated in a similar manneras in the preceding embodiment. Thus, sheds of the warp strings z andthe bias threads B are formed successively from below while insertion ofthe weft x by the weft rapier 17 is performed as shown in FIGS. 26 and27. After completion of insertion of the weft x for all of the stages,the yarn supporting plate 3 is drawn up by one pitch so that a conditionsimilar to that shown in FIG. 23 is entered. A similar sequence ofoperations are thereafter repeated so that weaving of the threedimensional fabric F proceeds.

Each of the screw shafts 15 and 16 of the bias thread feeding device 14of the two embodiments described above may be replaced by anotherstructure employing a rod 18 formed in a spiral shape as shown in FIG.28. The screw shafts 15, 16 may be, alternately, substituted by thestructure employing a device wherein yarn guides 20 for engagement withbias threads B project predetermined distances from an outer peripheralface of a belt 19 driven by a motor M as shown in FIG. 29. In thismodification, the bias threads B may be successively moved by apredetermined pitch by movement of the belt 19. Meanwhile, the numbersof layers of the warp strings z and layers of the bias threads B and thepositional relationship between them may be modified arbitrarily so longas at least one layer of warp strings z and one set of bias threads Bare present. Further, in place of the provision of the tension adjustingdevices 12 between the guide plate 11 and the bias thread beams 2acorresponding to the individual bias threads B, a structure may beemployed wherein bias threads B are individually drawn out from mutuallyindependent bobbins and variations in thread tension which take place inthe bias threads B in response to operation of the bias thread feedingdevice 14 are absorbed by rotation of the bobbins, or the verticalthreads y and the wefts x may be inserted using shuttles.

EMODIMENT 3

A third embodiment will be described with reference to FIGS. 30 to 33. Athree dimensional fabric F of the present embodiment has a similarstructure to that of the three dimensional fabric F of the firstembodiment except for the difference in arrangement and structure ofbias thread layers. In particular, bias threads B of one of two sets ofbias thread layers (the set disposed at the lower stage) are disposedsuch that they are folded back at the opposite end portions in awidthwise direction of the three dimensional fabric F in a similarmanner as in the first embodiment while bias threads B of the other setare disposed such that they are folded back intermediately of the widthof the three dimensional fabric F. A portion at which the bias threads Bare disposed makes a 5-axis three dimensional fabric wherein an in-plane4-axis fabric is coupled by the vertical threads y, but the otherportion at which the bias threads B are not disposed makes a 3-axis(only X, Y and Z) fabric, rather than a 5-axis fabric. Further, aportion of the three dimensional fabric F at which no bias thread ispresent because the bias threads B are folded back intermediately has athickness smaller by a distance corresponding to thickness of two layersof the bias threads B.

The three dimensional fabric F is used as a composite material whereinit is impregnated with a resin or the like, and due to the presence ofthe bias threads B disposed in inclined directions with respect to thelongitudinal direction of the fabric. The amount of deformation by aforce acting in an oblique direction is reduced as compared to acomposite material wherein a conventional 3-axis three dimensionalfabric is employed as the core. Further, a portion having acomparatively great number of layers of the bias threads B is greater inthickness and is particularly high in strength. While the fabric of FIG.30 includes the warp strings z of four columns and three rows and twosets of layers of the bias threads B, the number of the layers of thewarp strings z and the bias threads B or the folded positions of thebias threads B are determined depending upon a size and requiredphysical properties of a composite material in which the threedimensional fabric is employed as a skeletal material. A multiplicity ofsets of bias thread layers may be disposed while the folded positions ofthe bias threads B of the individual sets are successively displaced sothat the entire three dimensional fabric may have a gradual variation inthickness in its widthwise direction.

The three dimensional fabric F of this type is woven in a substantiallysimilar manner as in the case of the first embodiment. Since the foldingwidth of the bias threads B are different for different bias threadlayers, the setting condition of the bias threads B upon starting ofweaving is different. The number of bias threads B of one set isrequired to be twice as much as the number of vertical threads y to beinserted in the width within which the set of the bias thread layer isfolded back. Since the number of vertical threads y of the threedimensional fabric F shown in FIGS. 30 and 31 is 5, the number of biasthreads B constituting insertion of bias threads B to be folded backover the full width must be 10.

The bias threads B are set in position on the screw shafts 15 and 16 inthe manner shown in FIG. 32. Further, since the number of bias threads Bto be folded back with a smaller width than the full width is requiredto be 8 because they correspond to four vertical threads y, they are setin position to the screw shafts 15 and 16 which are set such that theyoverlap in a smaller extent with each other as shown in FIG. 33. Fromthis condition, weaving is performed in a manner to that described aboveso that the three dimensional fabric F is woven.

EMBODIMENT 4

The fourth embodiment will be described with reference to FIGS. 34 and35. A three dimensional fabric F of the present embodiment issignificantly different from the three dimensional fabrics F of thepreceding embodiments. In this embodiment, bias threads B constitutingindividual bias thread layers are individually folded back at samepositions intermediate of a weaving width of the three dimensionalfabric F. The bias threads are disposed also at the remaining portionsoutside the folded position of the bias threads B. As shown in FIG. 34,layers of the bias threads B are constituted from different groups ofthe bias threads B on the right-hand side portion and the left-hand sideportion of the three dimensional fabric F. The bias threads B of theindividual groups are folded back at mutually adjacent positions to eachother. Accordingly, with the present three dimensional fabric F, atightening force of the bias threads B is exhibited also at a centralportion in addition to the opposite side edge portions of the fabric F.The fiber density in the inside of the three dimensional fabric F isincreased and also the strength at such portion is improved comparingwith the case wherein the same bias thread layer is constituted from aset of bias threads B.

When the bias threads B are to be disposed on the remaining portionoutside the folded position of the bias threads B in the present threedimensional fabric F as follows. Two sets of bias thread feeding devices14 are required in order to constitute same bias thread layers as shownin FIG. 35, and the bias threads B are moved independently for each biasthread group.

In this embodiment, the folded position of the bias thread layer may bedisplaced in a widthwise direction of the three dimensional fabric F. Inthis structure, a portion where no bias thread is inserted may beprovided at a mid location of the three dimensional fabric F.

In case the folded position of a bias thread layer is displaced for eachgroup of the bias thread layers and besides bias threads are disposedover the full width, an action of the bias threads B to tighten thethree dimensional fabric F in the widthwise directions is distributed inthe widthwise directions by way of the vertical threads y, and the threedimensional fabric F obtained has a uniform fiber density. Further, aweft x may be inserted not only into a loop portion at a folded end of avertical thread y inserted in a folded condition between adjacentcolumns of warp strings z but also between each warp z and bias threadB. This increases the density of the wefts x as in the three dimensionalfabric F of the second embodiment. Alternatively, warp strings z may bedisplaced at a remaining portion of a folded layer of bias threads B inplace of bias threads.

EMBODIMENT 5

The fifth embodiment will be described with reference to FIGS. 36 to 41.A three dimensional fabric F of the present embodiment is different inarrangement and structure of bias thread layers from any of the threedimensional fabrics F of the preceding embodiments. Bias threads Bprovided in a plurality of sets each including two layers are all foldedback at end portions in widthwise directions of the three dimensionalfabric F, and an upper bias thread layer and a lower bias thread layerare formed from continuous bias threads B. The bias threads B in theupper layer and the lower layer are arranged such that they are inclinedsymmetrically with respect to each other. Meanwhile, bias thread layersof one set of two layers are cyclically inverted in their direction ofinclination. The inclination angles defined between the warp strings zand the bias threads B constituting the bias thread layers of aplurality of sets are not equal among all of the sets. Three kinds ofsets are present in this embodiment. One type of set has an inclinationangle is 45 degrees as shown in FIG. 37, the second as an inclinationangle is 60 degrees as shown in FIG. 38 and the third has an inclinationangle is 30 degrees as shown in FIG. 39. Thus, an in-plane 8-axis fabricis constituted from the wefts x having an inclination anglecorresponding to 90 degrees, the bias threads B and the warp strings z.

The three dimensional fabric F includes, in addition to the warp stringsz, wefts x and vertical threads y, a plurality of sets of bias threadswith each set constituted from two layers which are arranged such thatthey may be inclined symmetrically to each other with respect thelongitudinal direction of the fabric in a plane parallel to the layersof the warp strings. The inclination angle of the bias thread layers ofat least one set is different from the inclination angles of the biasthread layers of the other sets. Thus, it has improved in-planeuniformly when compared to an in-plane 4-axis, totally 5-axis threedimensional fabric,. When a three dimensional fabric F is used as a coreof a composite material which employs a resin or the like as a matrix,the amount of deformation by a force acting in an oblique direction uponthe composite material is further reduced by an action of the biasthreads. Consequently, the fabric has a wide range of application as astructural member. Because the bias thread layers within one set areformed by a multiplicity of bias threads B folded back continuously, thecomposite material has good rigidity against a tensile load, a bendingload and some other loads and is thus improved in strength.

An apparatus for weaving the three dimensional fabric is basically thesame as that of the first embodiment except for the numbers of the biasthread beams 2a and of sets and so forth of the screw shafts 15 and 16constituting the bias thread feeding device 14 are greater correspondingto the number of sets of bias thread layers.

An outline of a weaving procedure will be described hereinafter. Thenumber of bias threads B in each set varies in accordance with theinclination angle of the bias threads B relative to the longitudinaldirection of the fabric. The numbers of bias threads B in each set whenthe angle of inclination is either 45 degrees or 60 degrees is given bythe formula {2(n-1)+2}. Wherein the number of vertical threads yinserted in a width within which the set of the bias thread layer isfolded back is represented by n. Since the number of the verticalthreads y of the three dimensional fabric F of the present embodiment is5, up to 10 bias threads B are required and are set in position on thescrew shafts 15 and 16 as shown in FIG. 40.

The number of bias threads B required when the inclination angle is 30degrees is given by the formula {4(n-1)+2}, wherein the number ofvertical threads y to be inserted in a width within which the set of thebias thread layer is folded back is represented by n. Since the numberof the vertical threads y is 5, up to 18 bias threads B are required andset in position on the screw shafts 15 and 16 as shown in FIG. 41.

Then, in the bias thread feeding device 14 for moving the bias threads Bsuch the inclination angles thereof with respect to the longitudinaldirection of the fabric, that is, to the longitudinal direction of thewarp strings z, may be 45 degrees, the screw shafts 15 and 16 are drivenso that the individual bias threads B may be moved by one pitch by onefeeding operation similarly as in the first embodiment. Meanwhile, inthe bias thread feeding device 14 for moving the bias threads B suchthat the inclination angles thereof may be 60 degrees, the screw shafts15 and 16 are driven so that the individual bias threads B may be movedby two pitches in one feeding operation. In other words, where theinclination angle of the bias threads B is 60 degrees, the screw shafts15 and 16 are rotated twice that of the case wherein the inclinationangle is 45 degrees.

On the other hand, when the bias threads B are to be moved such that theinclination angle may be 30 degrees, the bias thread feeding device 14rotates, by a single feeding operation, the screw shafts 15 and 16 byone half that of the case wherein the inclination angle is 45 degrees sothat the individual bias threads B may be moved by a half pitch.However, in a condition after the bias threads B are moved by a halfpitch, they are disposed between the warp strings z and will interferewith insertion of the vertical threads y, and accordingly, the biasthread feeding device 14 for moving the bias threads B which arearranged at an inclination angle of 30 degrees is driven not so that thebias threads B may be moved by a half pitch for each insertion of thevertical threads y but so that the bias threads B may be moved by onepitch for each two times of insertion of the vertical threads y. As aresult, the bias threads are arranged in a similar manner as in the casewherein they are moved by a half pitch for each time of insertion of thevertical threads y as shown in FIG. 39. It is to be noted that, when thebias thread feeding device 14 is operated in such a manner as describedabove, the bias threads B are arranged at such an inclination angle asdescribed above in case the warp strings z and the wefts x have the samethickness and are arranged in the same pitch. In this instance, where athin thread comparing with the warp strings z, the wefts x and the biasthreads B which are arranged at the inclination angle of 45 degrees isemployed for the bias threads B which are arranged at the inclinationangles of 30 degrees and 60 degrees, the snaking of the threads isreduced and the fiber charging rate can be increased.

EMBODIMENT 6

The sixth embodiment will be described with reference to FIG. 42. Inthis embodiment, the vertical thread rapier 9 employs a structurewherein, as shown in FIG. 42, pipes 9a are mounted in front and rearrows on a support body 10 such that vertical threads y are threadedalternatively through the front and rear pipes 9a.

In the preceding embodiments, the vertical threads y are inserted at atime between the warp strings z and the bias threads B by way of thepipes 9a arranged in a row. In such structure, the distance between thewarp strings z and the bias threads B is so small that it is necessaryfor the pipes 9a to push aside and advance between the warp strings zand the bias threads B in lateral directions. Therefore, there is a fearthe warp strings z and the bias threads B cannot escape in lateraldirections and the pipes 9a may rub against the warp strings z and thebias threads B to damage the warp strings z and the bias threads B.However, where such structure is employed, since the warp strings z andthe bias threads B can escape when they are acted upon by laterallyacting forces from the pipes 9a, the pipes 9a do not rub stronglyagainst the threads. The pipes 9a may be arranged in three or more rowswhile the warp strings y may be inserted at a distance or every two ormore pipes a. Further, the vertical thread rapier may be divided into aplurality of groups for which an insertion timing is displaced or intowhich the wefts may be inserted from the opposite front and rear facesides of the three dimensional fabric.

Alternatively, as the vertical thread rapier 9, a structure may beemployed wherein a plate-formed member having guide holes formed at anend thereof is secured to the support body 10 in place of the pipes.

EMBODIMENT 7

A seventh embodiment will be described with reference to FIGS. 43 to 60.As shown in FIGS. 43 and 44, a three dimensional fabric F of thisembodiment is composed of a warp thread layer including a multiplicityof warp strings z. The warp strings are arranged in a plurality ofcolumns and a plurality of rows (four columns and two rows in FIG. 43)which extend parallel to a longitudinal direction of the threedimensional fabric F. A bias thread layer having a multiplicity ofcontinuous bias threads B are disposed in an inclined relationship withrespect to the longitudinal direction of the fabric in a plane parallelto the warp thread layer. A plurality of vertical threads y are disposedin a thicknesswise direction of the fabric such that theyperpendicularly intersect the warp strings z between and on the oppositeouter sides of the individual columns of the warp layer and continuousfor individual columns. In other words, in contrast to the threedimensional fabric F of the preceding embodiments, the three dimensionalfabric F of the present embodiment includes no weft x and is formed as a4-axis three dimensional fabric. The bias threads B are folded back atend portions in the widthwise direction of the three dimensional fabricF such that each two layers may make one set, and the upper bias threadlayer and the lower bias thread layer are constituted from thecontinuous bias threads B while each of the layers has an inclination ofone direction and the bias threads B of the upper and lower layers aredisposed such that they may be inclined symmetrically to each other.Each of the vertical threads y is inserted from above the threedimensional fabric F in a folded condition forming a loop at an endthereof. A selvage thread S is inserted in the end loop portion of thevertical thread y in order to attempt to prevent coming off of the endloop. Also the selvage thread S is inserted in a folded conditionforming a loop at an end thereof. It is to be noted that, while the warpstrings z, vertical threads y and bias threads B are shown in a spacedrelationship from each other in FIG. 43 in order to make the structureclear, actually the threads are held in a closely contactingrelationship with each other as shown in FIG. 44. Further, where a fiberbundle roving which has little twist like carbon fiber is employed forthe threads, the selvage threads S and the vertical threads y which areinserted in a folded condition forming loops at ends thereof areoverlapped, after weaving, with each other so that they are individuallyintegrated with each other as shown in FIG. 44.

In the three dimensional fabric F, in-plane isotropy of in-plane 3-axesis obtained by the warp strings z and the bias threads B which arearranged such that they are inclined symmetrically to each other, andthe structure is simplified compared to an in-plane 4-axis, totally5-axis three dimensional fabric. Consequently, it is easy to make thebias threads thick, and the fiber orientation ratio of the bias threadscan be raised. Then, if the bias threads are made thick comparing withthose of an in-plane 4-axis, totally 5-axis three dimensional fabric,where the three dimensional fabric is used as a composite material inwhich a resin or the like is impregnated, the composite materialobtained is improved in strength in oblique directions and is toughagainst shearing compression in the longitudinal direction.

A process of producing the three dimensional fabric F described abovewill now be described. An apparatus for weaving the three dimensionalfabric includes, as shown in FIGS. 45 and 46, a warp supplying sectionand thread supplying section 2. The warp supplying section includes anumber of warp beams 1 corresponding to the number of rows of the warpstrings z. The bias thread supplying section 2 includes a number of biasthread bobbins 2b equal to the number of the bias threads B forsupplying bias threads B each two of which make a set. This apparatusalso includes a yarn supporting plate 3 to which end portions of amultiplicity of warp strings z drawn out from the warp beams 1 and endportions of a multiplicity of bias threads B drawn out from the biasthread bobbins 2b is moved. As weaving proceeds, in a direction to drawup the three dimensional fabric F (to the left in FIGS. 45 and 46) by anaction of a driving mechanism (not shown) from a position adjacent to acloth fell frame 4 disposed at a predetermined location. A verticalthread rapier 9 is disposed to the rear of the cloth fell frame 4 (tothe right in FIGS. 45 and 46) and inserts, by upward and downwardmovement thereof, vertical threads y drawn out from a vertical threadsupplying section 8 into the individual columns of the warp strings z.Further, a selvage thread S to be inserted into an end loop of each ofthe vertical threads y is inserted in a folded condition forming a loopat an end thereof by a selvage thread rapier 58 (shown in FIG. 59).

A frame 59 and a guide plate 60 are disposed between a lower position ofthe vertical thread rapier 9 and the bias thread supplying section 2. Apluarlity of elongated holes 60a are formed in the guide plate 60 forpermitting lateral movement of the bias threads B. The number ofelongated holes 60a corresponds to the number of sets of the biasthreads B. A multiplicity of warp guide rollers 61 are disposed betweenthe frame 59 and the guide plate 60. The number of guide rollers 61corresponds to the number of stages which corresponding to the number ofrows of the warp strings z. The support shafts of the guide rollers 61extend in upward and downward directions while the warp guide rollers 61are arranged, at each of the stages, by a number corresponding to thenumber of columns of the warp strings z. The warp beams 1 are arrangedat locations to the side of the warp guide rollers 61 such that axesthereof may extend in parallel to the longitudinal direction of thethree directional fabric F. The warp strings z are drawn out from thewarp beams 1 in directions perpendicular to the longitudinal directionof the three dimensional fabric F. The then are diverted by 90 degreesby the guide rollers 61 such that they are directed toward the clothfell side. They are then supplied to the cloth fell by way of guideholes 62a formed in a warp guide 62 secured to the frame 59 so that thewarp strings z maybe guided one by one.

A bias thread feeding device 14 for moving the bias threads B of eachlayer is provided at a location of the frame 59 opposing to the biasthread supplying section 2. The bias thread feeding device 14 is shownin FIGS. 47 to 54. It includes a pair of upper and lower rails 63 and 64secured to the frame 59 such that they extend in a widthwise directionof the fabric. Guide blocks 65 serve as engaging portions andaccommodated at two upper and lower stages each by five between the tworails 63 and 64. As shown in FIG. 48, the rails 63 and 64 have guidegrooves 63a and 64a formed therein in an opposing relationship to eachother and extending in longitudinal directions thereof, and the guideblocks 65 can be slidably moved along the guide grooves 63a and 64a inan engaged condition with the guide grooves 63a and 64a. Each of theguide blocks 65 has an insertion hole 65a formed therein in which a biasthread B is to be threaded.

A pair of grooves 66 are formed in on opposite sides of the rails 63 and64 and extend in longitudinal directions of the rails 63 and 64(widthwise directions of the fabric). A pair of operating members 67 and68 extend vertically perpendicular to the rails 63 and 64. The operatingmembers are disposed within the grooves 66 such they are movable bothvertically and in the longitudinal directions of the rails 63 and 64.The rails 63 and 64 are driven by an action of a driving device (notshown). Further, restricting members 63b and 64b for restrictingmovement of the guide blocks 65 by an amount greater than a necessaryamount as shown in FIG. 47 project from the rails 63 adn 64,respectively.

A recessed portion 67a which can accommodate a central portion of aguide block 65 therein is formed at a location of the one operatingmember 67 corresponding to the guide block 65 at the lower stage whenthe operating member 67 is disposed at its standby position. Anotherrecessed portion 68a which can accommodate a central portion of a guideblock 65 therein is formed at a location of the other operating member68 corresponding to the guide block 65 at the upper stage when theoperating member 68 is disposed at its standby position. In particular,the guide blocks 65 disposed at the two upper and lower stages each byfive guide blocks are disposed such that four of each are opposed toeach other while the respective ends are displaced from each other. Inorder to prevent interference of the vertical thread rapier 9 with thewarp strings z and the bias threads B when the vertical threads y areinserted, the insertion holes 65a of the upper and lower guide blocks 65in each pair and the guide holes 62a formed in the warp guide 62 arepositioned in the same line in the upward and downward directions. It isto be noted that the two operating members 67 and 68 are provided acrossa plurality of bias thread feeding devices 14 and the guide blocks 65 ofthe individual bias thread feeding devices 14 are operated in asynchronized condition.

A pair of sprocket wheels 69 and 70 are disposed at locationscorresponding to each of the elongated holes 60a to the rear of theguide plate 60, and a chain 71 is stretched between the sprocket wheels69 and 70 such that it extends in parallel to the rails 63 and 64. Thechain 71 has support brackets 72 integrally formed at some of linkplates thereof, and the bias thread bobbins 2b of the bias threadsupplying section 2 are supported on support shafts 73 secured to thesupport brackets 72. When the sprocket wheels 69 and 70 are in astopping condition, the bias thread boddins 2b are arranged one by oneat locations corresponding to the opposite sides of the sprocket wheels69 and 70 as shown in FIG. 55. The remaining bias thread bobbins 2b aredisposed at upper and lower symmetrical locations spaced by an equaldistance from each other. A guide piece 74 is secured to each of thesupport shafts 73 such that it extends to a location forwardly of a biasthread bobbin 2b. A guide hole 74a for guiding a bias thread B drawn outfrom a corresponding bias thread bobbin 2b is formed in the guide piece74 such that it may be positioned on an extension line of an axis of thebias thread bobbin 2b. Then, the one sprocket wheel 69 is rotatedintermittently in a fixed direction in synchronism with driving of thebias thread feeding device 14 by a motor not shown.

The weaving of a three dimensional fabric by an apparatus having thestructure described above will be described next.

First, the feeding of the bias threads B by the bias thread feedingdevice 14 will be described. In FIG. 49, one of the guide blocks 65 atthe lower stage is accommodated in the recessed portion 67a of the oneoperating member 67 while another one of the guide blocks 65 at theupper stage is accommodated in the recessed portion 68a of the otheroperating member 68. From this condition, if the first operating member67 is moved upwardly while the second operating member 68 is moveddownward each by a distance equal to the height of the guide blocks 75,then the guide blocks 65 which remain in engagement with the operatingmembers 67 and 68 are moved integrally with the operating members 67 and68 so that a condition shown in FIG. 50 is entered. Subsequently, theother support member 68 is moved outwardly (in the direction of an arrowmark in FIG. 50) so that the engagement between the recessed portion 68athereof and the guide block 65 is canceled and a condition shown in FIG.51 is entered. In this instance, since the guide block 65 which has beenin engagement with the recessed portion 68a is restricted from movementby the restricting member 64b, the engagement between the recessedportion 68a and the guide block 65 is canceled with certainty bymovement of the operating member 68. Thereafter, the support member 68is moved upward again so that the condition of FIG. 52 is enteredwherein the recessed portion 68a thereof corresponds to a guide block 65at the upper stage.

From this condition, the first operating member 67 is moved outward andthe second operating member 68 is moved inwardly in a mutuallysynchronized relationship. Consequently, the guide blocks 65 at thelower stage are moved leftward in FIG. 52 by a pressing force of theoperating member 68 while the engagement between the guide block 65disposed at an end at the upper stage and the recessed portion 67 of theoperating member 67 is canceled so that the condition shown in FIG. 53is entered. Subsequently, the operating member 67 is moved downward to aposition at which the recessed portion 67a thereof corresponds to one ofthe guide blocks at the lower stage so that the condition shown in FIG.54 is entered. From this condition, the operating member 67 is movedinward so that the guide blocks 65 at the upper state are moved to theright in FIG. 54 by a pressing force of the operating member 67. Then,the condition of FIG. 49 is restored wherein the guide block 65 disposedat the end at the upper stage is engaged with the recessed portion 68aof the operating member 68 and the guide block 65 disposed at the end atthe lower stage is engaged with the recessed portion 67a of theoperating member 67, thereby completing lateral movement of the biasthreads B by one pitch. After then, the guide blocks 65 are movedcirculatively in a predetermined direction along a loop-formed route ofmovement to successively perform lateral feeding operation of the biasthreads B in a similar manner.

By the operation described above, the engaging portions between the biasthreads B and the guide blocks 65 are moved from the lower layer side ofthe upper layer side at one end in the widthwise direction of the threedimensional fabric F (on the first operating member 67 side). Meanwhile,they are moved from the upper layer side to the lower layer side at thesecond end (on the second operating member 68 side). They are moved inthe fixed directions opposite to each other at the upper layer and thelower layer, the bias threads B which constitute bias thread layers areput into a condition wherein each layer has an inclination of onedirection.

The sprocket wheels 69 and 70 of the bias thread supplying section 2 aredriven in synchronism with lateral feeding operation of the bias threadsB by operation of the bias thread feeding device 14. The individual biasthread bobbins 2b are moved together with movement of the individualguide blocks 65. Accordingly, no twisting (crossing) will take place inroutes of the individual bias threads B from the bias thread bobbins 2bto the cloth fell by way of the guide blocks 65.

Subsequently, a weaving procedure will be described. Upon starting ofweaving of a three dimensional fabric F, the yarn supporting plate 3 isdisposed at a position in the proximity of the cloth fell frame 4. Thewarp strings z drawn out from the warp beams 1 are set into a conditionwherein they are threaded through the warp guide rollers 61 and theguide holes 62a of the warp guide 62 and are secured to the yarnsupporting plate 3. The bias threads B drawn out from the bias threadbobbins 2b are threaded through the guide holes 74a, the elongated holes60a and the bias thread feeding device 14 and are secured to the yarnsupporting plate 3.

FIG. 57 shows a condition after insertion of the vertical threads y forthe fourth layer of the three dimensional fabric F is completed, and inthis condition, the vertical thread rapier 9 is disposed at its liftedposition. In this condition, the bias thread feeding device 14 is drivenas described hereinabove so that the individual bias threads B are movedby one pitch in widthwise directions of the three dimensional fabric.

Subsequently, the vertical thread rapier 9 is moved downward so that thevertical threads y are inserted between and onto the opposite outersides of the columns of the warp strings z as shown in FIG. 58.Thereupon, the individual pipes 9a of the vertical thread rapier 9 areinserted between the bias threads B behind intersecting portions of thebias threads B disposed in a mutually intersecting condition. That is,adjacent the bias thread feeding device 14 as shown in FIG. 46.

Subsequently, the selvage thread S is inserted into the end loops of thevertical threads y below the warp strings z at the lowermost stage bythe selvage thread rapier 58. Since the selvage thread rapier 9 isspaced from the location of the cloth fell, the vertical threads 6 arenot arranged in a perpendicularly intersecting condition to the warpstrings z to the cloth fell position only by downward movement of thevertical thread rapier 9 and remain in a spaced condition from the clothfell position. However, by insertion of the selvage thread S to thelowermost stage, the vertical threads y are arranged at the cloth fellposition so that they may be put into a perpendicularly intersectingcondition to the warp strings z. It is to be noted that, beforeinsertion of the selvage thread S is performed, beating may be performedto move the vertical threads y to the cloth fell side in advance. Thevertical thread rapier 9 is moved to its lifted position so that thevertical threads y are folded back upwardly. When the vertical threadrapier 9 is moved to the lifted position, the vertical threads yextending from the vertical thread rapier 9 to the cloth fell aredisposed obliquely with respect to the cloth fell as shown in FIG. 60.However, a rod (not shown) which is disposed in parallel to the rows ofthe warp strings z above the warp strings z at the uppermost stage ismoved to the cloth fell in a condition wherein it engages with thevertical threads y until the vertical threads y are disposed in parallelto the cloth fell. Then the thread supporting late 3 is moved so thatthe three dimensional fabric F is moved by one pitch until an endportion thereof is put into a condition shown in FIG. 57. Thereafter, asimilar sequence of operations are repeated so that the threedimensional fabric F having a structure substantially the same as thethree dimensional fabric F shown in FIGS. 43 and 44 is woven. Thedifference from the three dimensional fabric F shown in FIGS. 43 and 44resides in that the number of rows of the warp strings z is greater byone and also in that the number of bias thread layers is greater by oneset.

It is noted that, as a feeding method of the bias threads B, a methodmay be employed of successively moving the bias threads B using two setsof screw shafts described hereinabove in connection with the individualembodiments wherein the 5-axis three dimensional fabric F describedabove is woven. Further, the bias thread feeding device 14 and the biasthread supplying section 2 of the present embodiment may be applied toweaving of a 5-axis three dimensional fabric or the like which includessuch wefts as described hereinabove.

Meanwhile, since twisting is applied upon releasing of the bias threadsB with such releasing method of the bias theads B as illustrated in FIG.56, the bias thread bobbins 2b may be mounted such that the axes thereofmay extend perpendicularly to the thread drawing out direction. In thisstructure, the bias threads B may be drawn out in circumferentialdirections of the bias thread bobbins 2b.

EMBODIMENT 8

An eighth embodiment will be described with reference to FIGS. 61 to 64.This embodiment, is significantly different than the seventh embodimentin that a pair of vertical thread rapiers 9 are provided at front andrear locations. In this condition, vertical threads Y inserted intopositions corresponding to spaces between and on the opposite outersides of the warp layer columns are divided into two groups. As aresult, mutual adjacent ones thereof may belong to different groupswhile inserting operation of the vertical threads Y of the two groups isformed alternately by the different vertical thread rapiers 9. Inparticular, one of the two vertical thread rapiers 9 includes two pipes9a while the other vertical thread rapier 9 includes three pipes 9a. Thetwo vertical thread rapiers 9 are operated alternately. Further, 6 biasthread sets B are used.

FIGS. 61 and 62 show a condition wherein the bias threads B are moved byone pitch by operation of the bias thread feeding device 14 aftercompletion of insertion of the vertical threads Y by the vertical threadrapier 9 which includes two pipes 9a. From this condition, the verticalthreads Y are inserted by the vertical thread rapier 9 which includesthree pipes 9a and the selvage thread S is inserted into end loops ofthe vertical threads Y. Insertion of every other one of the verticalthreads Y and feeding operation of the bias threads B in a widthwisedirection are performed alternately in this manner, and the bias threadsB are arranged so that they may make an inclination angle of 60 degreeswith respect to the warps z.

Three dimensional fabric F woven in this manner is constituted suchthat, as shown in FIGS. 63 and 64, the warps z and the bias threads Bconstituting three axes in plane intersect each other at an angle of 60degrees, and can thus be obtained as a totally 4-axis three dimensionalfabric F including the vertical threads Y. The three dimensional fabricF has effects that the fiber charging ratio can be readily increased andthe thickness of the bias threads B can be increased comparing with a5-axis fabric and that, where it is used for a composite material, thestrength against a force acting in an oblique direction is improved andthe strength against shearing compression in the longitudinal directionis increased.

It is to be noted that insertion of the vertical threads dividedalternately into two groups may be performed alternately from theopposite direction of the front and rear faces of the woven fabric sothat the selvage thread S may be formed on the front and rear faces ofthe woven fabric, and the vertical threads Y may be inserted using ashuttle, in which case the selvage thread is unnecessary.

We claim:
 1. A three dimensional fabric comprising:a warp layerincluding a plurality of warps (z) arranged in parallel with alongitudinal direction of said fabric; bias thread layers including amultiplicity of continuous bias threads (B) arranged in such a manner asto be inclined symmetrically to each other with respect to thelongitudinal direction of said fabric in a plane parallel to said warplayer, each two of said bias thread layers making a set; and a pluralityof vertical threads (Y) arranged in a thicknesswise direction of saidfabric in perpendicularly intersecting condition to said warps (z)between all adjacent columns of said warp layer and on the oppositeouter sides of said columns, said vertical threads being continuousindividually for said columns.
 2. A three dimensional fabriccomprising:a warp layer including a plurality of warps (z) arranged inparallel with a longitudinal direction of said fabric; bias threadlayers including a multiplicity of continuous bias threads (B) arrangedin such a manner as to be inclined symmetrically to each other withrespect to the longitudinal direction of said fabric in a plane parallelto said warp layer, each two of said bias thread layers making a set; aplurality of vertical threads (Y) arranged in a thicknesswise directionof said fabric in perpendicularly intersecting condition to said warps(z) between all adjacent columns of said warp layer and on the oppositeouter sides of said columns, said vertical theads being continuousindividually for said columns; and a weft (x) arranged in a widthwisedirection of said fabric in a perpendicularly intersecting conditionwith said warps (z).
 3. A three dimensional fabric according to claim 1or 2, wherein said bias thread layers exist by a plurality of sets, andthose of said bias threads (B) which constitute at least one set of saidbias thread layers are folded back intermediately of the full width ofsaid fabric.
 4. A three dimensional fabric according to claim 2, whereinsaid bias thread layers exist by a plurality of sets, and those of saidbias thread layers of at least one set are folded back with apredetermined width smaller then the width of said fabric such that thethickness of said fabric varies in its widthwise direction.
 5. A threedimensional fabric according to claim 1 or 2, wherein said bias threads(B) constituting each of said bias thread layers each two of which makea set are disposed such that may have an inclination of one direction.6. A three dimensional fabric according to claim 1 or 2, wherein it hasa plurality of sets of said bias thread layers each two of which make aset, and the inclination angle of said bias threads (B) of those saidbias thread layers of at least one set is different from the inclinationangle of said bias threads (B) of those of said bias thread layers ofthe other set or sets.
 7. A method for producing a three dimensionalfabric wherein:a plurality of warps (z) are stretched in a plurality oflayers in a thicknesswise direction of said fabric in a conditionwherein they extend in a longitudinal direction of said fabric; aplurality of bias threads (B) are stretched in parallel to said warplayers such that each two layers may make a set; a vertical thread (Y)is inserted in the thicknesswise direction of said fabric and a loop isformed at an end thereof; a selvage thread is inserted into the end loopof said vertical thread (Y); then said vertical thread (Y) is drawnback; then, in a condition wherein said vertical thread (Y) connectingto said fabric being is woven is disposed outside said warps (z) andsaid bias threads (B), by an action of a feeding device arranged in thewidthwise direction of said fabric between the cloth fell position and abias thread supplying section, the engaging positions of said biasthreads (B) with a set made of each two thereof which are in an engagingcondition with engaging portions of said feeding device are moved by apredetermined pitch in opposite directions to each other for each ofsaid bias thread layers along the widthwise direction of said fabric toarrange said bias threads (B) obliquely with respect to the longitudinaldirection of said fabric; and then insertion of said vertical thread (Y)is performed again.
 8. A method for producing a three dimensionalfabric, wherein:a plurality of warps (z) are stretched in a plurality oflayers in a thicknesswise direction of said fabric in a conditionwherein they extend in a longitudinal direction of said fabric; aplurality of bias threads (B) are stretch in parallel to said warplayers such that each two layers may make a set; insertion of a verticalthread (Y) in the thicknesswise direction of said fabric and insertionof a weft (x) in a widthwise direction of said fabric are performed; ina condition wherein, after completion of insertion of said weft (x) byone cycle, said vertical thread (Y) connecting to said fabric beingwoven is disposed outside said warps (z) and said bias threads (B), byan action of a feeding device arranged in the widthwise direction ofsaid fabric between the cloth fell position and a bias thread supplyingsection, the engaging positions of said bias threads (B) with a set madeof each two thereof which are in an engaging condition with engagingportions of said feeling device are moved by a predetermined pitch inopposite directions to each for each of said bias thread layers alongthe widthwise direction of said fabric to arrange said bias threads (B)obliquely with respect to the longitudinal direction of said fabric; andthen insertion of said vertical thread (Y) is performed again.
 9. Amethod for producing a three dimensional fabric according to claim 7 or8, wherein, when said bias threads (B) are to be arranged obliquely withrespect to the longitudinal direction of said fabric, by an action of afeeding device which is arranged in the widthwise direction of saidfabric between the cloth fell position and said bias thread supplyingsection and wherein engaging portions which are provided at tow stagesso that they may be engaged with said bias threads (B) of each of saidbias thread layers each two of which make a set are circulatively movedin a predetermined direction along a moving route in the form of loopextending in the widthwise direction of said fabric, the engagingpositions of said bias threads (B) which are in an engaging conditionwith said engaging portions of said feeding device are moved in theopposite directions to each other between adjacent ones of said biasthread layers while said bias threads (B) connecting from said engagingportions to said thread supplying section are moved, upon movement ofsaid engaging portions, in the same direction.
 10. A method forproducing a three dimensional fabric according to claim 7 or 8, whereinsaid bias threads (B) each two of which make a set are stretched by aplurality of sets and, when said bias threads (B) are to be arrangedobliquely with respect to the longitudinal direction of said fabric byan action of a feeding device, the feeding pitch of a feeding devicecorresponding to at least one of said plurality of sets of said biasthreads (B) is made different from the feeding pitch of any otherfeeding device.